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Veritas Construction Inc ES-4011.03 <br /> June 17, 2016 Page 7 <br /> Revised June 22, 2016 <br /> With respect to the subject site, the areas meeting the definition of a "medium to high" landslide <br /> hazard (15 to 40 percent or greater slopes) are located mostly in the southwest corner and <br /> along the west and north margins of the site. It should be noted, during our fieldwork and <br /> reconnaissance of the surrounding slope areas, we did not observe signs of deep seated slope <br /> instability. Dense and competent till soils are prevalent throughout the upland and surrounding <br /> slope areas of the site. <br /> Mass grading activities will involve fills on the order of roughly 20 to 40 feet to establish design <br /> grades near areas characterized as a landslide hazard. Based on review of the preliminary site <br /> plan, slopes to be constructed on the north margin of the proposed development are expected <br /> to be sloped no steeper than three horizontal to one vertical (31-1:1V); the base of the slope is <br /> expected to be set back 25 feet from the north property line. Slopes to be constructed on the <br /> west and other surrounding areas of the proposed development are expected to be sloped no <br /> steeper than two horizontal to one vertical (21-1:1V). A storm water detention vault will be <br /> constructed on the north area of the site but, to the east of an existing ravine located in the <br /> northwest area. During construction of the detention vault, an ESNW representative should <br /> observe the slopes of the excavation and surrounding areas for signs of instability and landslide <br /> potential. During our subsurface exploration, native soils observed at test pit locations near the <br /> area of the site designated as landslide hazards consisted of medium dense to dense silty sand <br /> with gravel (SM) generally in the upper three to seven feet below existing grades underlain by <br /> very dense "unweathered" glacial till. These soils generally do not exhibit excessive instability. <br /> Per EMC 37.080C (Permitted Alterations), alterations within designated landslide hazard areas <br /> can only occur if the planned development will not create a hazard to the site and surrounding <br /> properties. Based on our review and investigation, it is our opinion that stability will be <br /> maintained and the potential for a landslide should be characterized as low provided our <br /> geotechnical recommendations are incorporated into final design. <br /> In addition, ESNW prepared a Stability Assessment letter, dated October 6, 2015, relating to <br /> the proposed stormwater detention vaults located on the north margin of the subject property. <br /> Slope stability analysis was completed as part of an overall evaluation for the proposed <br /> detention vaults in the referenced letter demonstrating acceptable stability for the static and <br /> seismic conditions is satisfied. <br /> Minimal Risk Statement <br /> Based on our understanding of the proposed development, in our opinion the proposed <br /> development will not increase the potential for soil movement, and the risk of damage to the <br /> proposed development or adjacent properties from soil movement will be minimal. This <br /> estimate does not cover unforeseen or changed conditions. <br /> Earth Solutions NW,LLC <br />